Creating Desktop Shortcuts Using Visual Basic

Once the Visual Basic 6.0 developer leaves the familiar array of features and services offered by the Visual Basic environment and by the more commonly used object models (such as DAO, ADO, or the more commonly used Microsoft Office object models), learning how to perform a particular task and selecting the appropriate technology to do it often becomes confusing. This is particularly true of creating desktop shortcuts. In this article, we'll examine how you can use Visual Basic to create desktop shortcuts programmatically (when your application or component is running) and as part of an installation program (using the Package and Deployment Wizard included with VB6).

Microsoft offers two technologies that the Visual Basic developer can use to create shortcuts. The first is the Shell Library, a collection of COM automation objects and standard C/C++ functions found in Shell32.dll. The library, however, is really geared toward the C/C++ developer. Much more accessible and straightforward is the Windows Scripting Host Object Library (wshom.dll), which in this case, merely wraps the IShellLink interface of Shell32.dll. Although Windows Script Host (WSH) is most commonly called by scripted languages, such as VBScript or JScript, most of its object model is also accessible from Visual Basic. WSH has the advantage of being a very "flat" object model; you don't have to navigate through an extensive hierarchy of objects to either instantiate or retrieve the object in which you're interested.

WSH offers two different objects that can be used in creating desktop shortcuts. The first is the WshShortcut object, which represents a shortcut to a file system object on the local computer or network. The second is the WshURLShortcut object, which represents a shortcut to an Internet resource. Either of these two objects is returned by the CreateShortcut method of the WSH Shell object. CreateShortcut requires a single argument, PathLink, the path and filename of the link file to be created or retrieved. So, the general code needed to instantiate a shortcut object is:

Dim sShortcutPath As String
Dim oShortcut As Object ' Use late binding to accommodate both
' WshShortcut and WshURLShortcut objects
Dim oShell As New WshShell
sShortcutPath = < path and filename of link file >
Set oSh = oScr.CreateShortcut(fn)

Note that this code uses late binding (oShortcut is declared to be of type Object, Visual Basic's generic object type, rather than the more specific WshShortcut or WshURLShortcut), since we don't know beforehand whether we're going to create a shortcut or an Internet shortcut. If you know in advance what type of shortcut your code will handle, you can, of course, use early binding. Alternatively, you can simply define your object to be of type WshShortcut and link it either to a local file system resource or to an Internet resource, since the target of a WshShortcut object can be defined either by a local filesystem path or by an Internet URL.

Whether CreateShortcut returns a WshShortcut object or a WshURLShortcut object depends on the file extension supplied with the PathLink argument. If the file extension is .lnk, CreateShortcut returns a WshShortcut object; if .url, it returns a WshURLShortcut object. Any other file extension generates an automation error. (You can, incidentally, extract the file extension easily by using the GetExtensionName method of the FileSystemObject object, found in the Microsoft Scripting Runtime Library, scrrun.dll. So, you could determine what type of link you're working with by using code such as the following:

If the argument supplied to the CreateShortcut object is the path and name of an existing file, then the property values of the WshShortcut or WshURLShortcut object are updated from the existing file. Otherwise, a new file is created. The WshShortcut object has the members shown in Table 1.

Table 1. Members of the WshShortcut Object

Member Name

Data Type

Description

Arguments Property

String

Any command-line arguments that are to be passed to the executable (defined by the TargePath property). To be meaningful, the target must be capable of recognizing the argument or arguments.

Description Property

String

A text description of the file. It is displayed in the Comments textbox of the link file's Properties dialog.

FullName Property

String

Read-only. The path and filename of the link file. The property value is set by the PathLink parameter of the WshShell object's CreateShortcut method.

Hotkey Property

String

A key combination that will automatically invoke the link. It typically consists of a special key (Alt, Ctrl, Shift), a plus sign, and a regular key or function key (F1, F2, etc.). For instance, the following code defines the Alt-F11 control key sequence as the hotkey for a link file:

oShortcut.Hotkey = "Alt+F11"

The Hotkey string is not case-sensitive.

IconLocation Property

String

The path and filename of an icon resource in an executable or dynamic link library, along with its zero=based index in the .exe or .dll. For instance, the following code assigns the third icon in Shell32.dll to the link

file:oShortcut.IconLocation = "C:\Windows\System32\Shell32.dll,2

Note that the value of the IconLocation property cannot be an icon (.ico) or other graphics file. If a value is not explicitly provided to the IconLocation property, it defaults to the first icon in the application defined by the TargetPath property or the application associated with the data file defined by the TargetPath property. If no icon is present, it defaults to the icon found at Shell32.dll,0.

Load Method

None

A hidden, private method. During instantiation, Load is called automatically by the CreateShortcut method if PathLink designates an existing file. Attempting to call the method in code generates a compiler error.

RelativePath Property

String

Write-only. Defines a target path and filename that are relative to the shortcut's path. This allows the target to be found if both shortcut and target are moved to new locations with the same relative relationship.

Save Method

None

Saves the current values of the link file. Its syntax is: WshShortcut.Save()

TargetPath Property

String

The target of the link. That is, the path and name of the executable, file, or folder to which the shortcut refers. For desktop shortcuts, this is typically the application launched when the user clicks on the shortcut.

WindowStyle Property

Long

An integer that defines the target's window style. This can also be a selected member of the WshWindowStyle enumeration.

It's important to note that, once you modify an existing shortcut's property values or assign property values to a new shortcut, the new shortcut property values are not actually written to the shortcut file until you call the Save method.